Suggest id(self).

primitives/test_primitives/sum.py

@@ -107,6 +107,9 @@ class SumPrimitive(base.SingletonOutputMixin[Inputs, Outputs, None, Hyperparams]
 
         # Primitive knows the port the container is listening on.
         connection = client.HTTPConnection(self.docker_containers[DOCKER_KEY], port=8000)
+        # This simple primitive does not keep any state in the Docker container.
+        # But if your primitive does have to associate requests with a primitive, consider
+        # using Python's "id(self)" call to get an identifier of a primitive's instance.
         connection.request('POST', '/', data, {
             'Content-Type': 'multipart/form-data',
         })